Development and Validation of First-Order Derivative and Area Under Curve Method by UV-Spectrophotometry for Quantification of Taurolidine in Pharmaceuticals

Analytical method development and validation constitute an essential component of analytical chemistry and play a decisive role in the discovery, development, and manufacture of pharmaceutical products. Official test methods emerging from these activities are routinely used by quality control laboratories to confirm the identity, purity, potency, and overall performance of drug products, all of which are essential prerequisites for ensuring drug safety and therapeutic efficacy. As regulatory expectations continue to tighten and pharmaceutical formulations grow increasingly complex, the demand for analytical procedures that are simple, rapid, sensitive, and economical—while still meeting internationally accepted validation criteria—has grown correspondingly.

1.1 Drug Profile: Taurolidine

Taurolidine is a synthetic antimicrobial compound derived from the amino acid taurine. It belongs to a class of broad-spectrum antimicrobial agents and exhibits activity against a wide range of Gram-positive and Gram-negative bacteria as well as fungi. The compound has found extensive clinical application in the prevention and treatment of infections associated with catheters, surgical procedures, and implanted medical devices, and it is particularly valued for its effectiveness in preventing catheter-related bloodstream infections (CRBSIs), where it is commonly employed as a catheter-lock solution. Beyond its antimicrobial action, Taurolidine possesses anti-inflammatory and anti-endotoxin properties that help mitigate tissue damage arising from microbial toxins.

Clinically, Taurolidine is used in the prevention and management of catheter-related infections, in the treatment of peritonitis (particularly among dialysis patients), and as an antimicrobial lock solution in indwelling medical devices. Reported adverse effects associated with its administration include local irritation, a burning sensation at the site of administration, nausea, hypersensitivity reactions, mild pain, and general discomfort.

1.2 Need for the Study

A number of analytical techniques including UV spectrophotometry, HPLC, RP-HPLC, LC-MS/MS, UPLC, RP-UPLC, and extraction spectroscopy have been reported for the estimation of Taurolidine in bulk and pharmaceutical dosage forms. However, most of these existing methods are expensive, time-consuming, and dependent on specialized instrumentation and trained personnel. To date, no specific first-order derivative or area under curve UV-spectrophotometric method has been reported for the estimation of Taurolidine. The present work was therefore undertaken to develop a straightforward, accurate, and precise first-order derivative method and area under curve method for Taurolidine using a UV-visible spectrophotometer, thereby providing the pharmaceutical industry with cost-effective alternatives to chromatographic techniques for routine quality control.

1.3 Aim and Objectives

The aim of the present work was to develop a simple, accurate, precise, and cost-effective UV-spectrophotometric method for the quantitative estimation of Taurolidine in bulk drug and pharmaceutical dosage forms. The specific objectives were as follows:

1. To develop and validate simple, precise, and accurate first-order derivative and area under curve (AUC) spectrophotometric methods for the estimation of Taurolidine in bulk drug and pharmaceutical dosage forms.
2. To confirm the reliability of both the first-order derivative and area under curve systems for quantifying Taurolidine using UV spectrophotometry.
3. To determine the wavelength of maximum absorption (λmax) of Taurolidine using UV spectroscopy.
4. To determine the linearity range, accuracy, precision, sensitivity, and robustness of the developed methods for Taurolidine in accordance with ICH Q2(R1) guidelines.
5. To construct standard calibration curves for Taurolidine over an appropriate concentration range.

2. REVIEW OF LITERATURE

A number of prior investigations have informed the analytical and pharmacological context of the present work. Woolfson et al. developed a sensitive reverse-phase HPLC method with fluorescence detection for the analysis of taurolidine degradation products and metabolites; the method demonstrated excellent linearity, low detection limits, and good recovery from plasma, supporting its suitability for the reliable quantitative analysis of taurultam and taurinamide in biological matrices [16].

Ozbek et al. developed and validated a rapid reverse-phase HPLC method for the determination of cisplatin using a C18 column with UV detection at 204 nm; the method exhibited excellent linearity over the concentration range of 20–150 µg/mL and was validated in accordance with ICH guidelines, confirming its suitability for routine quantitative analysis [17].

Caruso et al. reported that Taurolidine exhibits broad-spectrum antimicrobial activity and effectively inhibits the adhesion of pathogens such as Escherichia coli and Staphylococcus aureus to epithelial cells, with the antimicrobial action mediated through active degradation products and strong binding to bacterial adhesion proteins [18].

Wang, Guo, and co-workers developed an optimized ultrasound-assisted extraction (UAE) method for taurine from Porphyra yezoensis, achieving a maximum yield of 13.0 mg/g under optimized conditions; the method demonstrated significantly higher extraction efficiency than conventional techniques, and the purified taurine was characterized using FTIR, mass spectrometry, and NMR analysis [19].

Collectively, these reports establish the pharmacological importance of Taurolidine and taurine-related compounds, while also confirming that chromatographic techniques although sensitive remain resource and time intensive, reinforcing the rationale for a simpler UV-spectrophotometric alternative such as the one developed in the present study.

3. DRUG PROFILE

IUPAC NAME: 4-[(1,1-dioxo-1,2,4-thiadiazinan-4-yl)methyl]-1,2,4-thiadiazinane 1,1-dioxide.

Molecular Formula: C7H16N4O4S2.

MOLECULAR WEIGHT: 284.36g\mol

CATEGORY: Taurolidine is a broad spectrum antimicrobial agent. It is commonly used for prevention and treatment of infection.

4. MATERIALS AND METHODS

4.1 Materials

A working standard of Taurolidine was procured from SM Pharma and Chemicals, Mumbai, India. Analytical-grade methanol and distilled water were used as solvents throughout the study. A Shimadzu UV-1900 UV-visible spectrophotometer fitted with matched 1 cm quartz cells was used for all spectrophotometric measurements.

4.2 Selection of Analytical Medium

Solubility and stability were the principal criteria applied for the selection of the analytical medium; the chosen solvent was required to completely dissolve the drug while maintaining its stability for a sufficient duration. Preliminary solubility trials were carried out using distilled water, dimethyl sulfoxide (DMSO), ethanol, and methanol. Taurolidine formed a precipitate in distilled water and was incompletely dissolved in DMSO and ethanol. Methanol, in contrast, completely dissolved the drug and produced good absorbance characteristics, and was therefore selected as the analytical solvent for the entire study.

4.3 Preparation of Standard Stock Solution

A standard stock solution of Taurolidine was prepared by accurately weighing 50 mg of the drug, dissolving it in methanol, and transferring the solution to a 50 mL volumetric flask; the volume was made up to the mark with methanol to obtain a stock solution of 1000 µg/mL. Working solutions in the concentration range of 15–90 µg/mL were prepared by appropriate dilution of the stock solution with methanol.

4.4 Determination of Wavelength of Maximum Absorption (λmax)

A standard solution of Taurolidine (15 µg/mL) was scanned separately over the wavelength range of 200–300 nm, and the absorbance was recorded. The drug exhibited an absorbance of 0.079 A within this scanning range, which was used as the basis for subsequent derivative and AUC measurements.

4.5 First-Order Derivative Method

Standard solutions of Taurolidine in the concentration range of 15–90 µg/mL were scanned, and the corresponding first-order derivative spectra were recorded. A calibration curve was constructed by plotting the derivative amplitude against the corresponding drug concentration.

4.6 Area Under Curve (AUC) Method

For the AUC method, the area under the absorption curve was calculated over the wavelength range of 200–300 nm for each standard solution in the concentration range of 15–90 µg/mL. The area under the curve for the 15 µg/mL solution was found to be 0.5660 within this wavelength range; a calibration curve was then constructed by plotting AUC values against the corresponding drug concentration.

4.7 Assay of Marketed Tablet Formulations

Ten tablets of Taurolidine, each containing 20 mg of drug, were accurately weighed and finely powdered. A quantity of powder equivalent to 50 mg of Taurolidine (575 mg of powdered sample) was transferred into a 50 mL volumetric flask and dissolved in a small volume of methanol. The resulting solution was filtered through Whatman filter paper to remove insoluble excipients, and the filtrate was diluted to volume with methanol to obtain a stock solution of 1000 µg/mL. Suitable aliquots of this stock solution were further diluted with methanol in 10 mL volumetric flasks to obtain working solutions in the concentration range of 15–90 µg/mL (15, 30, 45, 60, 75, and 90 µg/mL), which were used to construct the assay calibration curves for both the first-order derivative and AUC methods.

4.8 Method Validation

Both developed methods were validated as per the International Council for Harmonisation (ICH) Q2(R1) guidelines with respect to linearity, accuracy, precision, sensitivity, and robustness. Linearity was assessed across the concentration range of 15–90 µg/mL. Accuracy was determined by recovery studies performed at 80%, 100%, and 120% of the target concentration. Precision was evaluated in terms of intra-day and inter-day %RSD values, and robustness was assessed by introducing small, deliberate variations in analytical conditions and observing their effect on the assay outcome.

5. RESULTS AND DISCUSSION

5.1 First-Order Derivative Method

The calibration curve for Taurolidine using the first-order derivative method was constructed over the concentration range of 15–90 µg/mL, as summarized in Table 1.

Table 1. Standard calibration data for Taurolidine by the first-order derivative method

Fig No. 1 - Calibration graph for Taurolidine by first order derivative   method

Application of the method to marketed tablet formulations (20 mg label claim) is summarized in Table 3

Fig No.14- Calibration graph for the assay of Taurolidine by First order derivative method.

Table 4. Standard calibration data for Taurolidine by the area under curve method

Sr. No.	Concentration (µg/mL)	Area Under Curve (AUC)
1	15	0.5660
2	30	0.7557
3	45	0.8400
4	60	0.9125
5	75	1.0040
6	90	1.4950

Fig 15.- Calibration graph for Taurolidine by area under curve method

Application of the AUC method to the assay of marketed tablet formulations is summarized in Table 6.

Fig No. 22- Calibration graph for the assay of Taurolidine by AUC  method.

The assay of marketed tablets by the AUC method gave an average value of 99.21 ± 0.62% of label claim, with a %RSD of 0.89, again within the pharmacopeial acceptance limits.

5.3 Comparative Evaluation

Both the first-order derivative and AUC methods proved effective for the quantification of Taurolidine in bulk drug and tablet dosage forms, with assay values close to 100% of the label claim in both cases, confirming their accuracy and reliability. The first-order derivative method demonstrated slightly superior precision, as reflected in its lower %RSD values, suggesting that it may be preferable for critical applications where reproducibility is paramount. The AUC method, while marginally less precise, remains an equally valid and simpler alternative, offering practical advantages in quality control laboratories handling high sample throughput. Overall, both validated methods are simple, accurate, precise, cost-effective, and compliant with ICH guidelines, positioning them as suitable alternatives to more expensive chromatographic techniques for the routine pharmaceutical analysis of Taurolidine.

6. CONCLUSION

This study successfully developed and validated two UV-spectrophotometric methods—the first-order derivative method and the area under curve (AUC) method—for the estimation of Taurolidine in bulk drug and tablet formulations. Analytical methods of this kind are essential for ensuring the quality, safety, and efficacy of pharmaceutical products, and UV spectrophotometry was selected for its simplicity, economy, and wide applicability in routine quality control, offering a practical alternative to more advanced chromatographic techniques.

Both methods were validated in accordance with ICH Q2(R1) guidelines and satisfied all key validation criteria. Linearity was excellent across the studied concentration range, recovery values were close to 100%, confirming the absence of excipient interference, and precision studies yielded low %RSD values. Robustness testing further confirmed that minor deliberate variations in analytical conditions did not materially affect assay accuracy.

The first-order derivative method demonstrated slightly better linearity and precision compared with the AUC method, although both approaches proved accurate, reliable, and cost-effective. These validated methods are therefore well suited to the routine quality control analysis of Taurolidine in bulk drug and pharmaceutical dosage forms, and may be recommended to quality control laboratories as simple, economical alternatives to chromatographic techniques.

ACKNOWLEDGEMENTS

The authors gratefully acknowledge Dr. S. R. Karajgi, Professor and Head, Department of Pharmaceutical Quality Assurance, for guidance and supervision throughout this work, and BLDEA's SSM College of Pharmacy and Research Centre, Vijayapura, for providing the necessary laboratory facilities.

CONFLICT OF INTEREST

The authors declare no conflict of interest.

REFERENCES

1. Verma G, Mishra M. Development and optimization of UV-Vis spectroscopy-a review. World J Pharm Res. 2018 Apr 19;7(11):1170-80.
2. Shabir GA, John Lough W, Arain SA, Bradshaw TK. Evaluation and application of best practice in analytical method validation. J Liq Chromatogr Relat Technol. 2007 Feb 1;30(3):311-33.
3. Bharti Mittu AC, Chauhan P, Chauhan P. Analytical method development and validation: a concise review. J Anal Bioanal Tech. 2015;6(01):1-5.
4. Sharma S, Goyal S, Chauhan K. A review on analytical method development and validation. Int J Appl Pharm. 2018 Nov 7;10(6):8-15.
5. Shrivastava S, Deshpande P, Daharwal SJ. Key aspects of analytical method development and validation. J Ravishankar Univ. 2018 May 1;31(1):32-9.
6. Chavan SD, Desai DM. Analytical method validation: a brief review. World J Adv Res Rev. 2022;16(2):389-402.
7. Kalra K. Method development and validation of analytical procedures. In: Quality Control of Herbal Medicines and Related Areas. 2011 Nov 4;4:3-16.
8. Konieczka P. The role of and the place of method validation in the quality assurance and quality control (QA/QC) system. Crit Rev Anal Chem. 2007 Aug 7;37(3):173-90.
9. Daksh S, Goyal A. Analytical method development and validation: a review. Chem Res J. 2020;5(3):173-86.
10. Ravisankar P, Gowthami S, Rao GD. A review on analytical method development. Indian J Res Pharm Biotechnol. 2014 May 1;2(3):1183.
11. Sanap GS, Zarekar NS, Pawar SS. Review on method development and validation. Int J Pharm Drug Anal. 2017 May 12;5(5):177-84.
12. Ravisankar P, Navya CN, Pravallika D, Sri DN. A review on step-by-step analytical method validation. IOSR J Pharm. 2015 Oct;5(10):7-19.
13. Chandran S, Singh RP. Comparison of various international guidelines for analytical method validation. Pharmazie. 2007 Jan 1;62(1):4-14.
14. Akash MS, Rehman K. Essentials of Pharmaceutical Analysis. Singapore: Springer; 2020.
15. Behera S, Ghanty S, Ahmad F, Santra S, Banerjee S. UV-visible spectrophotometric method development and validation of assay of paracetamol tablet formulation. J Anal Bioanal Tech. 2012 Oct 31;3(6):151-7.
16. Woolfson AD, et al. RP-HPLC method with fluorescence detection for the analysis of taurolidine degradation products and metabolites. [Journal, volume, and year to be confirmed by author].
17. Ozbek SS, et al. Development and validation of an RP-HPLC method for the determination of cisplatin using a C18 column and UV detection. [Journal, volume, and year to be confirmed by author].
18. Caruso F, et al. Broad-spectrum antimicrobial activity of taurolidine and inhibition of bacterial adhesion to epithelial cells. [Journal, volume, and year to be confirmed by author].
19. Wang F, Guo XY, et al. Optimized ultrasound-assisted extraction of taurine from Porphyra yezoensis. [Journal, volume, and year to be confirmed by author].
20. International Conference on Harmonisation (ICH). Q2(R1): Validation of Analytical Procedures: Text and Methodology. Geneva: ICH; 2005.
21. Indian Pharmacopoeia Commission. Indian Pharmacopoeia. Ghaziabad: IPC; latest edition.